R9C1 can only be <6>

R1C1 can only be <3>

R8C1 can only be <9>

R5C1 can only be <8>

R2C1 can only be <7>

R1C2 is the only square in row 1 that can be <6>

R3C7 is the only square in row 3 that can be <7>

R3C8 is the only square in row 3 that can be <9>

R7C7 is the only square in row 7 that can be <9>

R4C3 is the only square in row 4 that can be <9>

R5C3 can only be <6>

R5C7 can only be <2>

R5C9 can only be <9>

R4C4 is the only square in row 4 that can be <2>

R9C8 is the only square in row 9 that can be <8>

Intersection of row 1 with block 3. The value <5> only appears in one or more of squares R1C7, R1C8 and R1C9 of row 1. These squares are the ones that intersect with block 3. Thus, the other (non-intersecting) squares of block 3 cannot contain this value.

R2C7 - removing <5> from <145> leaving <14>

R2C9 - removing <5> from <1245> leaving <124>

Intersection of row 3 with block 2. The values <34> only appears in one or more of squares R3C4, R3C5 and R3C6 of row 3. These squares are the ones that intersect with block 2. Thus, the other (non-intersecting) squares of block 2 cannot contain these values.

R2C4 - removing <4> from <458> leaving <58>

Squares R7C5<34>, R8C4<345>, R8C6<135> and R9C5<14> in block 8 form a comprehensive locked quad. These 4 squares can only contain the 4 possibilities <1345>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the block.

R7C4 - removing <345> from <34568> leaving <68>

R7C6 - removing <35> from <3568> leaving <68>

Intersection of block 8 with row 8. The value <5> only appears in one or more of squares R8C4, R8C5 and R8C6 of block 8. These squares are the ones that intersect with row 8. Thus, the other (non-intersecting) squares of row 8 cannot contain this value.

R8C3 - removing <5> from <235> leaving <23>

R8C7 - removing <5> from <145> leaving <14>

R8C9 - removing <5> from <1245> leaving <124>

Squares R2C7 and R8C7 in column 7 form a simple locked pair. These 2 squares both contain the 2 possibilities <14>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the column.

R4C7 - removing <1> from <156> leaving <56>

R6C7 - removing <14> from <1456> leaving <56>

R6C8 is the only square in row 6 that can be <4>

R4C8 is the only square in block 6 that can be <1>

Squares R1C5 and R1C9 in row 1 and R9C5 and R9C9 in row 9 form a Simple X-Wing pattern on possibility <1>. All other instances of this possibility in columns 5 and 9 can be removed.

R2C9 - removing <1> from <124> leaving <24>

R3C5 - removing <1> from <1234> leaving <234>

R8C9 - removing <1> from <124> leaving <24>

Squares R2C9 and R8C9 in column 9 form a simple locked pair. These 2 squares both contain the 2 possibilities <24>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the column.

R1C9 - removing <2> from <125> leaving <15>

R9C9 - removing <4> from <145> leaving <15>

Intersection of block 9 with row 8. The value <4> only appears in one or more of squares R8C7, R8C8 and R8C9 of block 9. These squares are the ones that intersect with row 8. Thus, the other (non-intersecting) squares of row 8 cannot contain this value.

R8C4 - removing <4> from <345> leaving <35>

R3C4 is the only square in column 4 that can be <4>

Squares R2C3 and R2C9 in row 2 and R8C3 and R8C9 in row 8 form a Simple X-Wing pattern on possibility <2>. All other instances of this possibility in columns 3 and 9 can be removed.

R3C3 - removing <2> from <128> leaving <18>

R7C3 - removing <2> from <235> leaving <35>

Squares R7C3 (XY), R7C5 (XZ) and R9C2 (YZ) form an XY-Wing pattern on <4>. All squares that are buddies of both the XZ and YZ squares cannot be <4>.

R9C5 - removing <4> from <14> leaving <1>

R7C2 - removing <4> from <245> leaving <25>

R9C9 can only be <5>

R1C5 can only be <2>

R9C2 can only be <4>

R1C9 can only be <1>

R7C8 can only be <2>

R1C8 can only be <5>

R3C5 can only be <3>

R2C7 can only be <4>

R2C9 can only be <2>

R8C7 can only be <1>

R8C9 can only be <4>

R7C5 can only be <4>

R7C2 can only be <5>

R7C3 can only be <3>

R4C2 can only be <7>

R8C3 can only be <2>

R4C6 can only be <6>

R6C2 can only be <1>

R4C7 can only be <5>

R7C6 can only be <8>

R6C4 can only be <3>

R6C7 can only be <6>

R6C3 can only be <5>

R3C2 can only be <2>

R6C6 can only be <7>

R8C4 can only be <5>

R7C4 can only be <6>

R3C6 can only be <1>

R8C6 can only be <3>

R2C4 can only be <8>

R2C3 can only be <1>

R3C3 can only be <8>

R2C6 can only be <5>